The present invention relates generally to maintenance equipment associated with train control and more specifically to a trainline integrity locomotive test assembly which integrates existing train control systems.
Whether a railroad is conducting a single locomotive test, or troubleshooting a short or open circuit somewhere along trainline conductors, conventional test procedures and techniques involve the use of conventionally known End-of-Train (EOT) device. As part of train operation, such conventional EOT devices are placed in the coupler of a last car of a train, and are configured to provide measured brake pipe pressure and measured trainline voltage back to a Head-End-Unit (HEU) of the train, through either the trainline wires or a data radio.
ECP brake systems on trains utilize the HEU, which is connected to a trainline to transmit power and control signals to the electro pneumatic brake devices on each of the cars. Accordingly, conventional HEUs include software for testing a signal quality on a trainline network. Such a device is described in U.S. Pat. No. 6,759,971, the disclosure of which is incorporated by reference in its entirety. Signals transmitted down the trainline command each node to transmit a calibration signal. Thereby, signal quality is determined based on the receipt of the calibration signal. Through the use of such EOTs, various system requirements, such as trainline integrity, communications validation, and trainline brake control may all be established, monitored and maintained.
Such EOT devices have been used conventionally for troubleshooting electrical problems with trainline conductors. Nevertheless, the use of EOT devices for this purpose can be problematic because conventional EOT devices weigh approximately 34 pounds or approximately 15.5 kilograms, and stand approximately three feet or approximately 0.9 meters tall. As a result, positioning and repositioning these EOT devices along the length of a train to trouble shoot electrical problems is both difficult and potentially dangerous. Additionally, such EOT devices are fairly limited because only one EOT device is needed for each train. Therefore, utilizing such EOT devices as a diagnostic tool is not practical. Furthermore, such EOT devices are expensive and their use as off-line; as a result, railroads typically do not have many spares. In the interest of preventing personal injury and property damage, a smaller, light-weight unit has particular utility.
A trainline integrity locomotive test device is provided that is configured to provide conventionally provided EOT device functionality required for a single locomotive test as well as functionality necessary for troubleshooting electrical problems in trainline electrical conductors, wherein the trainline integrity locomotive test device includes a reduced number of components in comparison with a conventional EOT device. As part of the transmission of trainline integrity data from the test device to the HEU, a communications heartbeat signal is substituted for brake pipe pressure conventionally detected by EOT devices, so as to provide an indication of data communication reliability as well as a mechanism for preventing the braking system from operating without an actual EOT device.
In accordance with at least one embodiment, the test device may be configured of solid state components and enclosed in a robust, light-weight, ergonomic enclosure to facilitate portability, increase reliability and improve ease of use.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.